Disclaimer: I am NOT an expert on church security. I just wanted to share with you an experience I had a few months ago.
I had to travel to Salt Lake City a couple of months ago for work, and during our down time, my co-workers and I went to see the Mormon Tabernacle Choir practice. Besides the soul-soothing music, I got to see first-hand how they handled security.
I was fortunate enough to attend one of Grossman's Sheepdog Seminars in June of 2016 and I don't know if the church security has attended any of the seminars, but I did get to see some of his suggestions in action. I witnessed no less than four "rings" of security around the building.
One of the things that he said during the Seminar was that church security teams need to be out in the public - they don't need to be threatening, but they need to be interacting with the guests. The first thing I noticed when I stepped onto the grounds was that there were multiple people greeting all of the guests. Not a single guest went without someone making eye contact and greeting them warmly. (Outermost ring)
The second thing I noticed was that if anyone was carrying a backpack or bag (other than a small purse), they were approached with a smile and asked to check it. The bag check was on the outer perimeter of the building and everyone who was asked to check their bag was escorted to the bag check. (Second ring)
At the door, anyone who had a purse, had their purse searched. But it was done with a smile and a kind word. (Third ring)
Inside the concert hall, they had people stationed throughout the rows, back to the performers, watching everyone in the audience. All with a smile on their faces, but their eyes missed nothing. Each section of seats had at least one person watching over them. (Fourth, and closest, ring)
What I found exceptional was that none of these security people looked like security people - the were people of all ages, both male and female - and they were all exceedingly polite. It was very much reminiscent of Roadhouse - "be nice until it's time to not be nice". In fact, if I had not spent time studying security and if I had not attended the Sheepdog Seminar, I might not have recognized this multi-layer approach to security.
The church did an excellent job of providing security disguised as outstanding customer service.
My hope is that more churches embrace the style of security that Lt. Dave Grossman advocates. Too many times, church security folks are dressed in their tacticool clothes, all clumped together inside the building drinking coffee. Spread out a bit, walk the parking lots, engage the parishioners and their guests in conversation. Be nice, but be aware. If you can identify the threat in the parking lot, you've gone a long way in hardening your church as a target.